that portion of the oral mucous membrane that covers and is attached to the necks of the teeth and the alveolar process of the jaws; demarcated from lining mucosa on the facial aspect by a clearly defined line that marks the mucogingival junction, and, in contrast to the lining mucosa, is keratinized and lighter in color; on the palatal surface, the gingiva blends imperceptibly with the palatal mucosa.